/*
 * Copyright (c) 1998, 2001, Oracle and/or its affiliates. All rights reserved.
 * ORACLE PROPRIETARY/CONFIDENTIAL. Use is subject to license terms.
 *
 *
 *
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 *
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 *
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 */

package javax.swing.colorchooser;

import javax.swing.*;
import javax.swing.event.*;
import java.awt.Color;
import java.io.Serializable;

/**
 * A generic implementation of <code>ColorSelectionModel</code>.
 *
 * @author Steve Wilson
 * @see java.awt.Color
 */
public class DefaultColorSelectionModel implements ColorSelectionModel, Serializable {

  /**
   * Only one <code>ChangeEvent</code> is needed per model instance
   * since the event's only (read-only) state is the source property.
   * The source of events generated here is always "this".
   */
  protected transient ChangeEvent changeEvent = null;

  protected EventListenerList listenerList = new EventListenerList();

  private Color selectedColor;

  /**
   * Creates a <code>DefaultColorSelectionModel</code> with the
   * current color set to <code>Color.white</code>.  This is
   * the default constructor.
   */
  public DefaultColorSelectionModel() {
    selectedColor = Color.white;
  }

  /**
   * Creates a <code>DefaultColorSelectionModel</code> with the
   * current color set to <code>color</code>, which should be
   * non-<code>null</code>.  Note that setting the color to
   * <code>null</code> is undefined and may have unpredictable
   * results.
   *
   * @param color the new <code>Color</code>
   */
  public DefaultColorSelectionModel(Color color) {
    selectedColor = color;
  }

  /**
   * Returns the selected <code>Color</code> which should be
   * non-<code>null</code>.
   *
   * @return the selected <code>Color</code>
   */
  public Color getSelectedColor() {
    return selectedColor;
  }

  /**
   * Sets the selected color to <code>color</code>.
   * Note that setting the color to <code>null</code>
   * is undefined and may have unpredictable results.
   * This method fires a state changed event if it sets the
   * current color to a new non-<code>null</code> color;
   * if the new color is the same as the current color,
   * no event is fired.
   *
   * @param color the new <code>Color</code>
   */
  public void setSelectedColor(Color color) {
    if (color != null && !selectedColor.equals(color)) {
      selectedColor = color;
      fireStateChanged();
    }
  }


  /**
   * Adds a <code>ChangeListener</code> to the model.
   *
   * @param l the <code>ChangeListener</code> to be added
   */
  public void addChangeListener(ChangeListener l) {
    listenerList.add(ChangeListener.class, l);
  }

  /**
   * Removes a <code>ChangeListener</code> from the model.
   *
   * @param l the <code>ChangeListener</code> to be removed
   */
  public void removeChangeListener(ChangeListener l) {
    listenerList.remove(ChangeListener.class, l);
  }

  /**
   * Returns an array of all the <code>ChangeListener</code>s added
   * to this <code>DefaultColorSelectionModel</code> with
   * <code>addChangeListener</code>.
   *
   * @return all of the <code>ChangeListener</code>s added, or an empty array if no listeners have
   * been added
   * @since 1.4
   */
  public ChangeListener[] getChangeListeners() {
    return listenerList.getListeners(ChangeListener.class);
  }

  /**
   * Runs each <code>ChangeListener</code>'s
   * <code>stateChanged</code> method.
   *
   * <!-- @see #setRangeProperties    //bad link-->
   *
   * @see EventListenerList
   */
  protected void fireStateChanged() {
    Object[] listeners = listenerList.getListenerList();
    for (int i = listeners.length - 2; i >= 0; i -= 2) {
      if (listeners[i] == ChangeListener.class) {
        if (changeEvent == null) {
          changeEvent = new ChangeEvent(this);
        }
        ((ChangeListener) listeners[i + 1]).stateChanged(changeEvent);
      }
    }
  }

}
